Viewing Conditions for Australia: Saturday's Lunar Eclipse Will be Briefest of Century

For the third time in a two-year timespan, a "blood moon" will cast an eerie glow above Earth this weekend.

The total lunar eclipse, which is set for early Saturday night, April 4, is the third in a "lunar tetrad," or four successive lunar eclipses with no partial lunar eclipses in between, according to Eric Edelman, the host of Slooh's live broadcast of the event beginning Saturday at 9 p.m. AEDT (6 a.m. EDT).

Slooh frequently airs live astronomy events by using community observatories from all around the world. For those unable view the total eclipse, you can watch the eclipse unfold live below. After the event concludes, Slooh will show a replay of the event.

According to Edelman, this eclipse will be a "Pacific Ocean spectacle" and it will be best seen from Eastern Australia, Japan, Hawaii, northeastern Russia and western Alaska. That is if the weather will cooperate.

A storm system and its rain will prevent Sydney, along with other parts of New South Wales and eastern Queensland from viewing the eclipse.

Showers and clouds will also hinder the eclipse from being seen in northwestern Western Australia. The clouds should remain just north of Perth, allowing for ample viewing.

The moon will first begin passing through the outermost portion of the Earth's shadow (what's known as the penumbral stage) at 8:01 p.m. AEDT, and viewers will notice a subtle dimming. It is when the moon gets to the dark, inner (umbral) shadow that stargazers will see a distinctive darkness spread across the moon around 9:15 p.m. AEDT.

This total eclipse will be known for its brevity, as the blood moon portion will last a little less than five minutes, making this the shortest total eclipse this century, Edelman said. From 10:58 p.m. AEDT to 11:02 p.m. AEDT is when those who crave celestial sightings will want to look to the sky to view the red moon.

"Totality" is when the moon is fully inside Earth's shadow. Some total eclipses last for more than an hour but the reason for the abbreviated totality period is a result of the fact that the moon is skimming the outskirts of Earth's shadow rather than passing centrally through it, according to NASA.

The blood moon moniker is derived from the red color that is cast over the moon from light refracting in Earth's atmosphere.

"The red portion of sunlight is what makes it through our atmosphere to the other side, bent toward the eclipsed moon, so that even though the moon is within Earth's shadow, the red portion of the sun's light can give the moon this ghostly illumination," Edelman said, adding that how red an eclipsed moon gets depends on the characteristics of the atmosphere on that day such as clouds, and temperature.

This is the second of nine lunar tetrads in the 21st century, with the third scheduled to begin in April 2032, Edelman said. The fourth and final lunar eclipse in this tetrad is set for Sept. 28, 2015.